Absorption refrigeration



Patented May '19, 1936 PATENT OFFICE ABSORPTION REFRIGERATION Glenn F. zellhoefer, Bloomington, 111.

No Drawing. Application April 18, 1935, Serial No. 17,066

ZClaims.

The present invention relates generally to a solvent material and a refrigerant mixture for absorption refrigerating machines, both of the two-fluid type and of the three-fluid type.

In absorption refrigeration there is required a solvent material adapted to remain liquid throughout the operation of the apparatus, and a refrigerant material adapted to have a liquid and a vapor phase in the cycles of operation,

adapted to be dissolved or absorbed in the solvent,

adaptedto be evaporated or boiled as a vapor from the solvent mixture and from the solvent, and adapted to be condensed from the vapor to a liquid. Numerous refrigerants and numerous solvents are known, as well as successful combinations of these.

The two-fluid absorptionmachineshave certain mechanical parts which may be omitted or which are not duplicated in three-fluid machines.

In a three-fluid machine, there is in addition to the two-fluid mixture a body of inert gas which is always gas, and which does not to any substantial extent dissolve in any of the components of the two-fluid composition, or in mixtures thereof.

The present invention is directed to a new solvent for absorption refrigeration, and to combinations thereof with refrigerants.

A particular object of the invention is the use of ethyl levulinate as a solvent.

Another object is the use of a combination of said solvent with the refrigerant dichloromonofluoromethane.

Examples of the two-fluid apparatus in which the new solvent material and the new combination may be used is disclosed in my co-pending application Serial No. 651,306, flled January 12, 1933, or in my U. S. Patent No. 1,895,698, issued January 31, 1933. Other examples may readily 40 be'cited, and will be known to those skilledin the art 'I'he two-fluid apparatus above referred to, briefly described, comprises a still in which a liquid mixture of solvent and refrigerant is heated to distill away as a vapor the refrigerant material, a condenser wherein said vapor is condensed to a liquid state, an evaporator wherein the resulting liquid is vaporized at reduced pressure to produce refrigeration, andan absorber o in which vapor of the refrigerant material containing added heat units (acquired in the refrigerating process) is again dissolved in the solvent material. Suitable heat exchanging and circulating means are included, and automatic controls 5 may be provided.

at 210 F, to 25mm and that the cooling unit use as individual materials in certain places andfor certain functions, and that they be mutually adapted for certain functions when they 'are in combination. Other qualities not essential to refrigeration, but pertinent to practical usage. control or limit the choice of solvent or refrigerant. such as odor, viscosity, heat capacity, boiling point, freezing point, volatility, cheniicalstability, reactivity, corrosive action, bility, toxicity, etc. 4 n 1 By considering the limitations herein set forth, and suggested, I have been able to utilize ethyl levulinate as a solvent, for practicalusage, in combination with the refrigerant dichloro'mo'nofluoromethane, which is little known.

The new solvent is herein named as ethyllevulinate. In order to leave no doubt as to its identity, its structural formula-is herein given:

The refrigerant herein specified is dich'loromonoiluoromethane. In order to leave no doubt as to its identity, its structural formula is herein given:

In the accompanying claims, the invention is set forth as a combination useful in absorption refrigeration. Itis to be understood that a simple adulteration of the new'solvent in its pure form.

either by reason of commercial impurities, or by addition of lesser quantitiesof other material.

useful also as'solvent. is permitted,'and such a Y composition is intended to fall within the scope of the present invention.

What I claim is: v 1. A refrigerant mixture for the absorption type of refrigeration apparatus consisting of ethyl levulinate as the essentially predominant solvent,

and dichloromonofluoromethane as a refrigerant.

' 2. A refrigerant mixture for the absorption type. of refrigeration apparatus consisting of ethyl .levulinate as the essentially predominant solvent, and, a volatile chemically stable halogenated hydrocarbon refrigerant soluble in said solvent. 

